Welcome to the Illinois Streamflow Assessment Model (ILSAM) web site. ILSAM produces statistical estimates
of flow quantity in Illinois streams. The ILSAM flow estimates are representative of long-term climatic conditions,
with base periods covering the past 50 years or more, but also account for recent man-made modifications to the
flow amount such as have been caused by reservoirs, water-supply withdrawals, and discharges from wastewater treatment plants.
Flow estimates may be obtained for thousands of stream locations within each major watershed.
Values may be updated periodically as a result of additional review and analysis or to account for recent changes in water
use or water resource development.
Long-term support for the development and maintenance of ILSAM has been provided by the Illinois Department of Natural Resources,
Office of Water Resources.
Step 1 Instructions for Selecting a Location: 1. Choose a watershed from the list below or click on a watershed in the map. 2. Select a stream from the list or click on a stream in the map. 3. Pick a mile from the list or click on a mile point in the map. Alternatively, enter a mile in the box provided. 4. Click the "Continue" button to choose a flow parameter, and then view data on that location.